U.S. patent number 6,612,938 [Application Number 09/947,290] was granted by the patent office on 2003-09-02 for composite golf club head.
This patent grant is currently assigned to Callaway Golf Company. Invention is credited to Matthew T. Cackett, Steven M. Ehlers, D. Clayton Evans, J. Andrew Galloway, Robert S. Gonczi, Richard C. Helmstetter, Daniel R. Jacobson, James M. Murphy, Herbert Reyes.
United States Patent |
6,612,938 |
Murphy , et al. |
September 2, 2003 |
Composite golf club head
Abstract
A golf club having a club head with a face component composed of
a plurality of plies of pre-preg material and having a striking
plate portion with a thickness in the range of 0.050 to 0.250
inches is disclosed herein. The golf club head also has a
coefficient of restitution greater than 0.8 under test conditions
such as the USGA test conditions specified pursuant to Rule 4-1e,
Appendix II, of the Rules of Golf for 1998-1999. The golf club also
has a crown component composed of a plurality of plies of pre-preg
material and a sole component composed of a plurality of plies of
pre-preg material.
Inventors: |
Murphy; James M. (Oceanside,
CA), Reyes; Herbert (Laguna Niguel, CA), Galloway; J.
Andrew (Escondido, CA), Evans; D. Clayton (San Marcos,
CA), Helmstetter; Richard C. (Rancho Santa Fe, CA),
Jacobson; Daniel R. (San Diego, CA), Ehlers; Steven M.
(Poway, CA), Cackett; Matthew T. (San Diego, CA), Gonczi;
Robert S. (Oceanside, CA) |
Assignee: |
Callaway Golf Company
(Carlsbad, CA)
|
Family
ID: |
32686323 |
Appl.
No.: |
09/947,290 |
Filed: |
September 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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877652 |
Jun 8, 2001 |
6440008 |
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474670 |
Dec 29, 1999 |
6248025 |
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958723 |
Oct 23, 1997 |
6010411 |
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Current U.S.
Class: |
473/324; 473/345;
473/349 |
Current CPC
Class: |
B29C
70/46 (20130101); A63B 53/0466 (20130101); B29C
70/865 (20130101); A63B 60/00 (20151001); B29C
70/342 (20130101); A63B 53/04 (20130101); A63B
53/0458 (20200801); A63B 2209/02 (20130101); B29L
2031/5227 (20130101); A63B 2053/0491 (20130101); A63B
53/0462 (20200801); A63B 2209/023 (20130101); A63B
53/0408 (20200801); A63B 53/0416 (20200801); A63B
53/0433 (20200801) |
Current International
Class: |
B29C
70/00 (20060101); B29C 70/46 (20060101); B29C
70/86 (20060101); B29C 70/34 (20060101); A63B
53/04 (20060101); B29C 70/04 (20060101); A63B
053/04 () |
Field of
Search: |
;473/324,345-349 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Blau; Stephen
Attorney, Agent or Firm: Catania; Michael A.
Parent Case Text
CROSS REFERENCES TO RELATED APPLICATIONS
This application is a continuation-in-part application of U.S.
patent application No. 09/877,652, filed on Jun. 8, 2001, now U.S.
Pat. No. 6,440,008, which is a continuation of U.S. patent
application Ser. No. 09/474,670, filed on Dec. 29, 1999, now U.S.
Pat. No. 6,248,025, which is continuation-in-part application of
U.S. patent application Ser. No. 08/958,723, filed on Oct. 23,
1997, now U.S. Pat. No. 6,010,411.
Claims
We claim:
1. A composite golf club head comprising: a face component composed
of a plurality of pre-preg plies having fibers, the plurality of
pre-preg plies ranging from 20 to 70 plies, the face component
having a striking plate portion and a return portion, the striking
plate portion having a thickness in the range of 0.010 inch to
0.250 inch, and the return portion tapering in thickness rearward
from a perimeter of the striking plate portion; a crown composed of
a plurality of pre-preg plies ranging from 3 to 20 plies, the crown
attached to the face component; a sole composed of a plurality of
pre-preg plies ranging from 3 to 20 plies, the sole having a ribbon
portion and a bottom portion, the bottomn portion of the sole
attached to the return portion of the face component and the ribbon
portion of the sole attached to the crown, the ribbon portion
having an upper portion approximately perpendicular to the crown
and a lower portion angled 25 degrees to 75 degrees relative to the
crown; a weighting member disposed within the plies of pre-preg of
the ribbon portion of the sole; and a sole plate attached to the
external surface of the bottom portion of the sole, the sole plate
composed of a metal material; wherein the striking plate portion
has an aspect ratio ranging from 1.0 to 1.7; wherein the golf club
head has a volume ranging fron 300 cubic centimeter to 450 cubic
centimeters; and wherein the golf club head has a coefficient of
restitution ranging from 0.80 to 0.93 under standard USGA
conditions.
2. The golf club head according to claim 1 wherein the striking
plate has a thicklness in the range of 0.100 inch to 0.200 inch,
and the striking plate portion is composed of 30 to 60 plies of
pre-preg.
Description
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a golf club head with a striking
plate composed of a composite material. More specifically, the
present invention relates to a golf club head composed of composite
material with specifically oriented sheets for more efficient
transfer energy to a golf ball at impact.
2. Description of the Related Art
One of the first (if not the first) disclosures of a golf club head
composed of a plurality of plies of a pre-preg material is Great
Britain Patent Application Number 1201648 which was filed in 1967
on behalf of William Charles Carlton.
In 1984, U.S. Pat. No. 4,449,707 issued to Hayashi et al., for a
Golf Club Head Of Carbon Fiber Reinforced Plastic, based on a
Japanese Patent Application originally filed in 1982. The Hayashi
Patent discloses surrounding a core with a fiber-reinforced fabric
to create a golf club head with a proper center of gravity.
Another disclosure is U.S. Patent Number 4,545,580 to Tomita et
al., for a Wood-Type Golf Club Head, based on a Japanese Patent
Application originally filed in 1983. The Tomita Patent discloses a
durable golf club head having an outer shell composed of a fiber
reinforced plastic material, a foam center core, and an
intermediate shell formed of a thermoplastic resin material.
Yet another disclosure is U.S. Pat. No. 4,630,826 to Nishigaki et
al., for Golf Club Head. The Nishigaki Patent discloses body
composed of a carbon resin layer and a cast resin layer with a face
insert block composed of a ceramic material.
Still another disclosure is U.S. Pat. No. 4,778,185 to Kurokawa,
for Wood-Type Core-Shell Golf Club Heads, based on a Japanese
Patent Application originally filed in 1984. The Kurokawa Patent
discloses a golf club head composed of a foam core and a shell
composed of a material fiber reinforced plastic having long and
short fibers.
Yet another disclosure is U.S. Pat. No. 4,793,616 to Fernandez, for
Golf Club. The Fernandez Patent discloses a club head shell
composed resin impregnated fibers and ceramic particles within the
resin to provide a high strength shell.
Yet another disclosure is U.S. Pat. No. 5,154,425 to Niskanen et
al., for a Composite Golf Club Head. The Niskanen Patent discloses
a club head composed of a metal matrix composite of a ceramic
matrix composite.
When a golf club head strikes a golf ball, large impacts are
produced that load the club head face and the golf ball. Most of
the energy is transferred from the head to the golf ball, however,
some energy is lost as a result of the collision. The golf ball is
typically composed of polymer cover materials (such as ionomers)
surrounding a rubber-like core. These softer polymer materials
having damping (loss) properties that are strain and strain rate
dependent which are on the order of 10-100 times larger than the
damping properties of a metallic club striking plate. Thus, during
impact most of the energy is lost as a result of the high stresses
and deformations of the golf ball (0.001 to 0.20 inches), as
opposed to the small deformations of the metallic club face (0.025
to 0.050 inches). A more efficient energy transfer from the club
head to the golf ball could lead to greater flight distances of the
golf ball.
The generally accepted approach has been to increase the stiffness
of the club head face to reduce metal or club head deformations.
However, this leads to greater deformations in the golf ball, and
thus increases in the energy transfer problem.
Some have recognized the problem and disclosed possible solutions.
An example is Campau, U.S. Pat. No. 4,398,965, for a Method Of
Making Iron Golf Clubs With Flexible Impact Surface, which
discloses a club having a flexible and resilient face plate with a
slot to allow for the flexing of the face plate. The faceplate of
Campau is composed of a ferrous material, such as stainless steel,
and has a thickness in the range of 0.1 inches to 0.125 inches.
Another example is Eggiman, U.S. Pat. No. 5,863,261, for a Golf
Club Head With Elastically Deforming Face And Back Plates, which
discloses the use of a plurality of plates that act in concert to
create a spring-like effect on a golf ball during impact. A fluid
is disposed between at least two of the plates to act as a viscous
coupler.
Yet another example is Jepson et al, U.S. Pat. No. 3,937,474, for a
golf Club With A Polyurethane Insert. Jepson discloses that the
polyurethane insert has hardness between 40 and 75 shore D.
Still another example is Inamori, U.S. Pat. No. 3,975,023, for a
Golf Club Head With Ceramic Face Plate, which discloses using a
face plate composed of a ceramic material having a high energy
transfer coefficient, although ceramics are usually harder
materials. Chen et al., U.S. Pat. No. 5,743,813 for a Golf Club
Head, discloses using multiple layers in the face to absorb the
shock of the golf ball. One of the materials is a non-metal
material.
Lu, U.S. Pat. No. 5,499,814, for a Hollow Club Head With Deflecting
Insert Face Plate, discloses a reinforcing element composed of a
plastic or aluminum alloy that allows for minor deflecting of the
face plate which has a thickness ranging from 0.01 to 0.30 inches
for a variety of materials including stainless steel, titanium,
KEVLAR.RTM., and the like. Yet another Campau invention, U.S. Pat.
No. 3,989,248, for a Golf Club Having Insert Capable Of Elastic
Flexing, discloses a wood club composed of wood with a metal
insert.
The Rules of Golf established and interpreted by the United States
Golf Association ("USGA") and The Royal and Ancient Golf Club of
Saint Andrews, set forth certain requirements for a golf club head.
The requirements for a golf club head are found in Rule 4 and
Appendix II. A complete description of the Rules of Golf is
available on the USGA web page at www.usga.org. Although the Rules
of Golf do not expressly state specific parameters for a golf club
face, Rule 4-1e prohibits the face from having the effect at impact
of a spring with a golf ball. In 1998, the USGA adopted a test
procedure pursuant to Rule 4-1e, which measures clubface COR. This
USGA test procedure, as well as procedures like it, may be used to
measure clubface COR.
Although the prior art has disclosed many club head composed of
composite materials, the prior art has failed to provide a golf
club head composed of a composite material that is lightweight,
forgiving and has a high coefficient of restitution.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a golf club head that is composed of
a composite material and is forgiving while providing better
performance that other composite golf club heads.
One aspect of the present invention is a composite golf club head
that includes a face component, a crown, a sole, weight member and
a sole plate. The face component is composed of a plurality of
pre-preg plies having fibers. The plurality of pre-preg plies range
from 20 to 70 plies. The face component has a striking plate
portion and a return portion. The striking plate portion has a
thickness in the range of 0.050 inch to 0.250 inch, and the return
portion tapers in thickness rearward from a perimeter of the
striking plate portion. The crown is composed of a plurality of
pre-preg plies ranging from 3 to 20 plies, and the crown is
attached to the face component. The sole is also composed of a
plurality of pre-preg plies ranging from 3 to 20 plies. The sole
has a ribbon portion and a bottom portion. The bottom portion of
the sole is attached to the return portion of the face component
and the ribbon portion of the sole is attached to the crown. The
weighting member is disposed within the plies of pre-preg of the
ribbon portion of the sole. The sole plate is attached to an
external surface of the bottom portion of the sole, and the sole
plate is composed of a metal material.
Another aspect of the present invention is a golf club head having
a body, a weight member, a sole plate and an internal tube. The
body is composed of a plurality of plies of pre-preg. The body has
a hollow interior defined by a striking plate, a crown, a sole, and
a ribbon. The body has a volume of 275 cubic centimeters to 600
cubic centimeters and has a mass under 150 grams. A weight member
may be disposed within the plies of pre-preg of the ribbon. The
weight member has a mass of from 15 grams to 100 grams. In a golf
club head having a volume of 600 cc, additional weighting is not
required. The sole plate is attached to an external surface of the
sole of the body. The sole plate is composed of a metal material
and has a mass of from 5 grams to 20 grams. The internal tube is
disposed within the hollow interior of the body. The internal tube
is composed of a metal material and has a mass of from 5 to 15
grams.
Yet another aspect of the present invention is a golf club head
including a face component, a crown component and a sole component.
The face component is composed of a plurality of pre-preg plies.
The face component has a striking plate portion and a return
portion. The return portion extends laterally rearward from a
perimeter of the striking plate. The striking plate portion has a
thickness in the range of 0.050 inch to 0.250 inch. The plurality
of plies of the face component include a plurality of face doubler
plies in a ninety degree orientation, a plurality of face doubler
plies in a zero degree orientation, a plurality of full face plies
in a positive forty-five degree orientation, a plurality of full
face plies in a negative forty-five degree orientation, and a
plurality of full face plies in a zero degree orientation. The
crown component is attached to an upper section of the return
portion of the face component. The sole component has a ribbon
portion and a bottom portion. The bottom portion of the sole
component is attached to a lower section of the return portion of
the face component and the ribbon portion of the sole component is
attached to the crown component.
Yet another aspect of the present invention is a golf club
including a golf club head, a shaft and a grip. The golf club head
has a volume of 275 cubic centimeters to 600 cubic centimeters. The
shaft has a tip end and a butt end, and is composed of a graphite
material. The tip end of the shaft is attached to the golf club
head. The grip is placed over a butt end of the shaft. The golf
club has a mass less than 290 grams, and the golf club head has a
coefficient of restitution ranging from 0.80 to 0.93 under standard
USGA conditions.
Yet another aspect of the present invention is a golf club head
including a face component, a crown and a sole. The face component
is composed of a plurality of pre-preg plies ranging from 20 to 70
plies. The face component has a striking plate portion and a return
portion. The return portion extends laterally rearward from a
perimeter of the striking plate. The striking plate portion has a
thickness in the range of 0.050 inch to 0.250 inch. The crown is
composed of a plurality of pre-preg plies ranging from 3 to 20
plies. The crown is attached to the face component and overlaps an
upper section of the return portion. The upper section of the
return portion extends rearward from the perimeter of the striking
plate portion a distance of at least 0.5 inch. The sole component
is composed of a plurality of pre-preg plies ranging from 3 to 20
plies. The sole component has a ribbon portion and a bottom
portion. The bottom portion of the sole component is attached to a
lower section of the return portion of the face component and the
ribbon portion of the sole component is attached to the crown
component. The lower section of the return portion extends rearward
from the perimeter of the striking plate portion a distance of at
least 0.5 inch. The golf club head has a coefficient of restitution
ranging from 0.80 to 0.93 under standard USGA conditions.
Having briefly described the present invention, the above and
further objects, features and advantages thereof will be recognized
by those skilled in the pertinent art from the following detailed
description of the invention when taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is an exploded view of a golf club head of the present
invention.
FIG. 2 is a front view of a golf club head of the present
invention.
FIG. 2A is a front view of a golf club head of the present
invention illustrating the aspect ratio of the golf club head.
FIG. 2B is a view of a golf club with attached shaft and grip of
the present invention.
FIG. 3 is a top plan view of a golf club head of the present
invention.
FIG. 4 is a heel end view of a golf club head of the present
invention.
FIG. 5 is a toe end view of a golf club head of the present
invention.
FIG. 6 is a bottom plan view of a golf club head of the present
invention.
FIG. 7 is a cross-sectional view of the golf club head of FIG. 3
along line 7--7.
FIG. 8 is a cross-sectional view of the golf club head of FIG. 2
along line 8--8.
FIG. 9 is an isolated cross-section view of a face preform of a
golf club head of the present invention.
FIG. 9A is an enlarged view of area A of FIG. 9.
FIG. 9B is an enlarged view of area B of FIG. 9;
FIG. 10 is an isolated cross-section view of a crown/face preform
of a golf club head of the present invention.
FIG. 11 is an isolated cross-section view of a sole preform of a
golf club head of the present invention.
FIG. 12 is a top plan view of a golf club head of the present
invention illustrating the variation in thickness of the walls of
the golf club head.
FIG. 13 is a front plan view of a golf club head of the present
invention illustrating the variation in thickness of the walls of
the golf club head.
FIG. 14 is a bottom plan view of a golf club head of the present
invention illustrating the variation in thickness of the walls of
the golf club head.
FIG. 15 is a heel end view of a golf club head of the present
invention illustrating the variation in thickness of the walls of
the golf club head.
FIG. 16 is a plan view of a face/crown ply having a ninety degree
orientation.
FIG. 17 is a plan view of a full face ply having a ninety degree
orientation.
FIG. 18 is a plan view of a face doubler ply having a ninety degree
orientation.
FIG. 19 is a plan view of a sole ply having a negative forty-five
degree orientation.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed at a golf club that has a large
volume and a minimum mass. The golf club has a golf club head that
is composed of a plurality of plies of pre-preg material, a
lightweight graphite shaft and a lightweight grip. The golf club
head is forgiving and has a high coefficient of restitution thereby
enabling for less dispersion and greater distance of a golf ball
hit with the golf club of the present invention.
As shown in FIGS. 1-6, a golf club head of the present invention is
generally designated 20. The club head 20 is either a fairway wood
or a driver. The drivers range in loft angle of from six degrees to
fifteen degrees. The club head 20 has a body 22 that is generally
composed of a composite material such as plies of carbon pre-preg
sheets. The body 22 has a crown 24, a striking plate 26, a sole 28
with a bottom portion 28a and a ribbon 30.The ribbon preferably has
an upper ribbon wall 30a and a lower ribbon wall 30b. The ribbon 30
generally extends from a toe end 32 to a heel end 34.The ribbon 30
generally begins at one end of the striking plate 26 and ends at an
opposite end of the striking plate 26. A rear 36 of the body 22 is
opposite the striking plate 26 and is defined by portions of the
ribbon 30, the crown 24 and the sole 28. Also, at the heel end 34
of the club head 20 is an internal tube 38 with an opening 39 for
placement of a shaft therein. The internal tube 38 is placed within
the hollow interior 44 of the body 22. Within the ribbon is a
weight member 40.
A sole plate 42 is disposed within a recess 29 of the bottom
portion 28a of the sole 28. The sole plate 42 is preferably
composed of a metal material such as aluminum or titanium, and
preferably has a mass of 5 grams to 20 grams. A preferred mass for
an aluminum sole plate 42 is approximately 11 grams, and a
preferred mass for a titanium sole plate 42 is approximately 18
grams. The sole plate 42 is preferably bonded within the recess 29
through use of adhesives. The sole plate 42 preferably has embossed
graphics thereon. The sole plate 42 increases the durability of the
club head 20 since the sole 28 often impacts the ground during the
striking of a golf ball.
The club head 20 of the present invention also has a greater volume
than a composite club head of the prior art while maintaining a
weight that is substantially lower or equivalent to that of the
prior art. The volume of the club head 20 of the present invention
ranges from 175 cubic centimeters to 600 cubic centimeters, more
preferably ranges from 300 cubic centimeters to 450 cubic
centimeters, and is most preferably 360 cubic centimeters for a
driver. The mass of the club head 20 of the present invention
ranges from 165 grams to 300 grams, preferably ranges from 175
grams to 225 grams, and most preferably from 188 grams to 195
grams. The body 22 of plies of pre-preg material has a mass ranging
from 80 grams to 150 grams, and most preferably 98 grams.
The volume of the present invention is increased by increasing the
vertical distance of the club head 20 from the sole 28 to the crown
24, as opposed to the horizontal distance of the heel end 34 to the
toe end 32. This increase in volume is brought about by the dual
wall structure of the ribbon 30. The upper ribbon wall 30a is
approximately perpendicular relative to the crown 24, while the
lower ribbon wall 30b preferably has angle between 25 degrees to 75
degrees relative to the crown 24. The greater volume of the club
head 20 allows the club head 20 to be more forgiving than prior art
golf club heads while providing better performance. The mass of
club head 20 is much less than metal club heads of similar volumes,
and allows the use of more discretionary mass to optimize mass
properties.
The striking plate 26 has a smaller aspect ratio than striking
plate plates of the prior art. The aspect ratio as used herein is
defined as the width, "w", of the striking plate divided by the
height, "h", of the striking plate 26, as shown in FIG. 2A. In one
embodiment, the width w is 90 millimeters and the height h is 54
millimeters giving an aspect ratio of 1.666. In conventional golf
club heads, the aspect ratio is usually much greater than 1. For
example, the original GREAT BIG BERTHA.RTM. driver had an aspect
ratio of 1.9. The aspect ratio of the present invention preferably
ranges from 1.0 to 1.7.
As shown in FIG. 7, the internal tube 38 lies within the hollow
interior 44 of the club head 20. The internal tube is preferably
composed of a metal material and has a mass ranging from 8 grams to
20 grams. The internal tube 38 is most preferably composed of
stainless steel and has a mass of approximately 14 grams. The
internal tubing 38 has a bore 130 to receive an insert and a shaft,
not shown, therein. Such an insert is discussed in U.S. Pat. No.
6,352,482 for a golf Club With Hosel Liner, which is hereby
incorporated by reference in its entirety, Preferably, the club
head 20 has a hollow interior 44 defined by the body 22, however,
the light weight of the composite body 22 allows for numerous
manipulations in placement of weight, foam, sound enhancing devices
and the like within the hollow interior 44.
Referring specifically to FIG. 1, the club head 20 has a weight
member 40 disposed within the plies of pre-preg that compose the
ribbon 30 of the club head 20. Preferably, the weight member 40 is
composed of three weight members 40a, 40b and 40c. One such weight
member 40 is described in U.S. Pat. No. 6,386,990, entitled A
Composite Golf Club Head With An Integral Weight Strip, which is
hereby incorporated by reference in its entirety. Another such
method is described in co-pending U.S. patent application Ser. No.
09/947,292, for Internal Weighting For A Composite Golf Club Head,
filed on Sep. 5, 2001, and hereby incorporated by reference in its
entirety. The weight member 40 has a mass ranging from 30 grams to
80 grams, more preferably 45 grams to 70 grams, and most preferably
54 grams. The weight member 40 is preferably composed of a metal
material integrated into a polymer medium. The metal material is
preferably selected from copper, tungsten, steel, aluminum, tin,
silver, gold, platinum, or the like. A preferred metal is tungsten
. The weight member 40 has a density greater than the composite
material of the body 22. Preferably, the weight member 40 extends
from approximately the heel end 34 of the striking plate 26 through
the rear 36 to the toe end 32 of the striking plate 26. However,
the weight member 40 may only extend along the rear 36 of the
ribbon 30, the heel end 34 of the ribbon 30, the toe end 32 of the
ribbon 30, or any combination thereof Those skilled in the
pertinent art will recognize that other weighting materials may be
utilized without departing from the scope and spirit of the present
invention.
The placement of the weighting members 40a-c allows for the moment
of inertia of the golf club head 20 to be optimized. A more
thorough description of the optimization of the moments of inertia
is disclosed in co-pending U.S. patent application Ser. No.
09/796,951, filed on Feb. 27, 2001, entitled High Moment of Inertia
Composite Golf Club, and hereby incorporated by reference in its
entirety. In one preferred example of the golf club head 20 of the
present invention, the moment of inertia about the Ixx axis through
the center of gravity is approximately 2566 grams-centimeters
squared ("g-cm.sup.2 "), the moment of inertia about the Iyy axis
through the center of gravity is approximately 1895 g-cm.sup.2, and
the moment of inertia about the Izz axis through the center of
gravity is approximately 3368 g-cm.sup.2.
As shown in FIGS. 8, 9, 9A and 9B, a return portion 100 is a
transition area from a perimeter 29 of the striking plate 26
rearward towards the crown 24. The return portion 100 has a
thickness ranging from 0.070 inch to 0.200 inch to control the
compliance of the striking plate 26. The return portion 100 has an
upper section 100a, a lower section 100b, a heel section 100c, not
shown, and a toe section 100d, not shown. The return portion 100
also has a taper region 101, which includes an upper tapering
region 101a, a lower tapering region 101b, a heel tapering region
101c, not shown, and a toe tapering region 101d, not shown. The
tapering region 101 tapers in thickness from a greater thickness
nearer the striking plate portion 26 to a lesser thickness rearward
toward the crown 24.
The return portion 100 has a predetermined length, which extends
rearward from the perimeter 29 of the striking plate portion 26
into the crown 24. Preferably, the distance of the return portion
100, Dr, ranges from 0.25 inch to 2.0 inches, more preferably from
0.5 inch to 1.75 inches, and most preferably 1.5 inches.
Preferably, the distance from the perimeter 29 to the beginning of
the tapering region 101 of the return portion 100 ranges from 0.25
inch to 1.5 inches, and most preferably 1.0 inch.
The body 22 manufactured from a face component 125, which includes
the striking plate portion 26 and the return portion 100, a crown
component 124 and a sole component 128. The crown component 124
overlaps the face component 125, as shown in FIG. 10. The sole
component 128 includes the ribbon portion 30 and the bottom portion
28a. The sole component 128 is attached to the crown component 124
and the face component 125.
FIGS. 16-19 illustrates preferred pre-preg sheets for forming the
composite body of the golf club head 20. FIG. 16 illustrates a
face/crown ply pre-preg sheet that is generally designated 55. The
face/crown ply 55 has a plurality of fibers 51 dispersed within a
resin body 53. The fibers 51 are preferably composed of a carbon
material. Alternatively, the fibers 51 may be aramid fibers, glass
fibers or the like. The resin is typically an epoxy material. The
relation of the fibers 51 to the striking plate 26, when the
striking plate 26 is in a position to strike a golf ball,
determines the orientation of the fibers 51. If the fibers 51 are
parallel with the ground, or in other words extending across from
the toe end to the heel end, then the face/crown ply 55 has a zero
degree orientation. If the fibers 51 are approximately
perpendicular to the ground, as shown in FIG. 16, or in other words
extending from the crown to the sole, then the face/crown ply 55
has a ninety degrees orientation.
FIG. 17 illustrates a full face ply pre-preg sheet that is
generally designated 57. As with the face/crown ply 55, the full
face ply 57 has a plurality of fibers 51 dispersed within a resin
body 53. The fibers 51 extend from the sole 28 to the crown 24, and
thus the full face ply 57 has fibers 51 that are perpendicular to
the ground when it is in a position for striking a golf ball.
Therefore, the full face ply 57 of FIG. 17 has a ninety degrees
orientation.
FIG. 18 illustrates a face doubler ply pre-preg sheet that is
generally designated 58. As with the face/crown ply 55, the face
doubler ply 58 has a plurality of fibers 51 dispersed within a
resin body 53. The fibers 51 extend from the sole 28 to the crown
24, and thus the face doubler ply 58 has fibers 51 that are
perpendicular to the ground when it is in a position for striking a
golf ball. Therefore, the face doubler ply 58 of FIG. 18 has a
ninety degrees orientation.
FIG. 19 illustrates a sole ply pre-preg sheet that is generally
designated 59. As with the face/crown ply 55, the sole ply 59 has a
plurality of fibers 51 dispersed within a resin body 53. The fibers
51 extend at a forty-five degree angle relative to the ground when
it is in a position for striking a golf ball. Therefore, the sole
ply 59 of FIG. 19 has a forty-five degree orientation.
As previously stated, the preferred composite material is plies of
carbon pre-peg sheets. Plies of pre-preg composite sheets are
manufactured by pulling strands of fiber in a parallel motion,
preferably carbon, aramid or glass fiber, through a resin film and
allowing the resin to partially cure or "stage". When the resin is
partially staged, the resin holds the fibers together such that the
fibers form a malleable sheet with all of the fibers in a specific
orientation relative to an edge of the sheet. Preferred
orientations are zero degrees, plus forty-five degrees, minus
forty-five degrees and ninety degrees. Exemplary carbon pre-preg
fiber sheets may be obtained from Newport Composites of Santa Ana,
California, Fiberite Inc. of Greenville, Texas, or Hexcel Inc. of
Pleasonton, California.
The manipulation of the thickness of the various regions of the
body 22 allows the golf club head 22 to have superior durability,
forgiveness and performance as compared to prior art composite golf
club heads. As shown in FIGS. 12-15, the thickness of the body 22
is focused on the striking plate portion 26. In a most preferred
example: the region designated A of the striking plate portion 26
has a thickness of approximately 0.169 inch; the region designated
B, at the junction of the crown 24 and striking plate 26 has a
thickness of approximately 0.188 inch; the region designated C of
the bottom portion 28a of the sole 28 has a thickness of
approximately 0.221 inch; the region designated D of the ribbon 30
and of the bottom portion 28a has a thickness of approximately
0.202 inch; the region designated E of the crown 24, the bottom
portion 28a and the ribbon 30 has a thickness of approximately
0.033 inch; and the region designated F of the crown 24 has a
thickness of approximately 0.191 inch. The regions designated Z1,
Z2, Z3, Z4, Z5 and Z6 are tapering zones where the thickness tapers
rearward.
The golf club head 20 is preferably manufactured using a bladder
molding process. One such process is described in U.S. Pat. No.
6,248,025, which is hereby incorporated by reference. However,
those skilled in the pertinent art will recognize that other
manufacturing methods may be utilized without departing from the
scope and spirit of the present invention.
The coefficient of restitution of the club head 20 of the present
invention under standard USGA test conditions with a given ball
ranges from 0.8 to 0.9, preferably ranges from 0.81 to 0.87 and is
most preferably 0.82.The coefficient of restitution (also referred
to herein as "COR") is determined by the following equation:
##EQU1##
wherein U.sub.1 is the club head velocity prior to impact; U.sub.2
is the golf ball velocity prior to impact which is zero; v.sub.1 is
the club head velocity just after separation of the golf ball from
the striking plate of the club head; v.sub.2 is the golf ball
velocity just after separation of the golf ball from the striking
plate of the club head; and e is the coefficient of restitution
between the golf ball and the club striking plate.
The values of e are limited between zero and 1.0 for systems with
no energy addition. The coefficient of restitution, e, for a
material such as a soft clay or putty would be near zero, while for
a perfectly elastic material, where no energy is lost as a result
of deformation, the value of e would be 1.0.The thickness of the
striking plate 26 and the orientation of the plies of pre- preg
determine the coefficient of restitution of the golf club head 20.
Additionally, the thickness of the return 100 of the golf club head
20 allows for a greater deflection in the striking plate 26 which
increases the coefficient of restitution of the golf club head 20.
The return 100 couples the striking plate 26 to the crown 24 which
reduces the loss of energy to the striking plate 26 during impact
with a golf ball. If the return 100 is too thick, the striking
plate 26 is isolated and rigid, thereby reducing the coefficient of
restitution. If the return 100 is too thin, failure of the striking
plate 26 may occur upon impact with a golf ball.
From the foregoing it is believed that those skilled in the
pertinent art will recognize the meritorious advancement of this
invention and will readily understand that while the present
invention has been described in association with a preferred
embodiment thereof, and other embodiments illustrated in the
accompanying drawings, numerous changes, modifications and
substitutions of equivalents may be made therein without departing
from the spirit and scope of this invention which is intended to be
unlimited by the foregoing except as may appear in the following
appended claims. Therefore, the embodiments of the invention in
which an exclusive property or privilege is claimed are defined in
the following appended claims:
* * * * *
References